vchoi_fork

[svn-r4090] 
Purpose:
    Implemented port hunting
    Really catch SIGPIPE signals
Description:
    Port hunting allows to try and bind to a successive port number
    if the port number given in the filename is already used.

    Because of a stupid typo in the code, SIGPIPE wasn't catched
    which might have caused the sending side to hang.
Solution:
    The Stream VFD's file access property list was extended by two
    elements:
      - maxhunt: how many successive ports to try if the one
                 given in the filename is already in use
                 Default is not to hunt for additional ports.
      - port:    port number which is finally used to bind a socket
                 This might be different to the port number
                 as given in the filename if port hunting is enabled.
                 The H5Pget_fapl_stream() can be used to obtain
                 this port number.
Platforms tested:
    x86 Linux, Irix 32/64 bit, Dec Alpha, Unicos on T3E, AIX on SP2
    Hitachi SR8000